Date: Tue, 05 Oct 2010 08:18:37 +0100
From: Steve Thompson <g8gsq@f2s.com>
Subject: Re: [Amps] Skin depth: silver plating of tank circuit coil
feasible with
Yes and no appears to be the answer - rf current doesn't take the
lowest possible resistance path, it crowds on the outside surface
of a conductor. Once there it appears to look for the lowest
resistance path.
Steve
## apparently, on a tubing type tank coil, it's supposed to bunch up on the
outside edge,and
at the same token there is supposed to be little or no RF flowing on the inside
walls of tubing
coils. Strap, on the other hand, will conduct RF on both sides. 3/8" wide
strap will handle as
much RF as 1/4" tubing....since both have the same circumference. I always
suspected that was
the case... then read it in the infamous VO stoke's TX book,,,, in the
appendix,
## IMO... I detest the look of plane, clean copper tubing,strap, in tank
circuits, or else where. It looks like
you built a house, then forgot to paint it. I use the cool-amp glop on all of
it. Some of the 3/8" tubing coils,
and straps of various widths.... [ up to 1.5" wide in some cases]. I did 10
years ago still have a perfect finish.
On the same subject, I have used cool-amp silver plating compound on relay
contacts, contactor's, sliding
contacts, buss bars etc, and in each case the DC resistance drops to nil. The
stuff works superb on open frame
relay contacts. Ever had relay contacts go open on RX.... but ok on
TX...like on a remote switch box ?
This stuff will cure it. After the contacts are 1st cleaned, I apply the
cool-amp glop. When done, an ultra thin layer
of their other product..called 'conducto-lube' is applied. Conducto-lube
is just pure ground up silver powder,
suspended in grease. Conducto lube is made for things like relay contacts,
sliding contacts, etc.
## You have to be careful with 'conducto lube'. Unlike Dow corning DC-4
grease, conducto-lube will
conduct..and very well. You don't want to be getting any on ceramic
insulators. I have seen several instances
of where cool-amp is used, where buss bars are overlapped, then bolted. Power
co's buy it by the case load.
Cool-amp has an indefinite shelf life. I use latex dentist gloves, when
applying the glop. Then you can get in there
with all your fingers, and really get it applied good. When done, rinse off
with warm water, then place on
paper towel's to dry. I usually try and do a whole bunch of straps and coils,
all in one sitting. The CU has to
be ultra clean 1st. Nothing looks better than a big tank coil, made from
1/4...3/8...1/2" tubing..when it has been
silver plated. Same deal with the wide/narrow strap.
Jim VE7RF
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